The invention relates to a method of detecting horizontal movements in the picture contents of time-sequential frames or fields composed of scanning lines of a picture signal.
If, for example, the transmission standard of a television signal is changed, or if several methods of improving the picture quality of a television signal are used, it is necessary to have information about the location of movements in areas of a picture and about the extent of these movements. This problem occurs in a stronger form in a television signal whose frames are formed as two successive fields generated in accordance with the interlaced scanning mode, because these two fields represent different movement phases of one possible movement. For example, if the vertical frequency of the television signal is doubled to suppress the large-area flicker, new pictures must be generated between the available fields of the television signal. If a movement which is possibly present in the pictures of the television signal is to be displayed correctly, it is necessary for generating the new pictures to know in which areas of the picture contents of the pictures a movement takes place and to what extent this movement takes place.
There are different methods of detecting movements in the picture contents of frames or fields of a television signal which generally operate two-dimensionally, i.e. they detect vertical as well as horizontal movements in the picture contents. These methods are generally very elaborate and therefore uneconomical, particularly for use in television receivers for consumer use.